Make accept() be nonblocking.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@313

diff --git a/coregrind/arch/x86-linux/vg_libpthread.c b/coregrind/arch/x86-linux/vg_libpthread.c
index 46d1c65a7949188e2c0faef47c58ff44d4b22212..6cd7e40d0cf91166c417c386cdbe5068b7953b04 100644 (file)
--- a/coregrind/arch/x86-linux/vg_libpthread.c
+++ b/coregrind/arch/x86-linux/vg_libpthread.c
@@ -61,6 +61,14 @@
 #include <sys/time.h>
 #endif
 
+
+/* ---------------------------------------------------------------------
+   Forwardses.
+   ------------------------------------------------------------------ */
+
+static void wait_for_fd_to_be_readable_or_erring ( int fd );
+
+
 /* ---------------------------------------------------------------------
    Helpers.  We have to be pretty self-sufficient.
    ------------------------------------------------------------------ */
@@ -1072,6 +1080,7 @@ int __libc_accept(int s, struct sockaddr *addr, socklen_t *addrlen);
 __attribute__((weak))
 int accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
+   wait_for_fd_to_be_readable_or_erring(s);
    return __libc_accept(s, addr, addrlen);
 }
 
@@ -1469,6 +1478,7 @@ int select ( int n,
 typedef unsigned long int nfds_t;
 #endif
 
+
 /* __attribute__((weak)) */
 int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 {
@@ -1552,6 +1562,21 @@ int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 }
 
 
+/* Helper function used to make accept() non-blocking.  Idea is to use
+   the above nonblocking poll() to make this thread ONLY wait for the
+   specified fd to become ready, and then return. */
+static void wait_for_fd_to_be_readable_or_erring ( int fd )
+{
+   struct pollfd pfd;
+   fprintf(stderr, "wait_for_fd_to_be_readable_or_erring %d\n", fd);
+   pfd.fd = fd;
+   pfd.events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLNVAL;
+   /* ... but not POLLOUT, you may notice. */
+   pfd.revents = 0;
+   (void)poll(&pfd, 1, -1 /* forever */);
+}
+
+
 /* ---------------------------------------------------------------------
    Hacky implementation of semaphores.
    ------------------------------------------------------------------ */

diff --git a/coregrind/vg_libpthread.c b/coregrind/vg_libpthread.c
index 46d1c65a7949188e2c0faef47c58ff44d4b22212..6cd7e40d0cf91166c417c386cdbe5068b7953b04 100644 (file)
--- a/coregrind/vg_libpthread.c
+++ b/coregrind/vg_libpthread.c
@@ -61,6 +61,14 @@
 #include <sys/time.h>
 #endif
 
+
+/* ---------------------------------------------------------------------
+   Forwardses.
+   ------------------------------------------------------------------ */
+
+static void wait_for_fd_to_be_readable_or_erring ( int fd );
+
+
 /* ---------------------------------------------------------------------
    Helpers.  We have to be pretty self-sufficient.
    ------------------------------------------------------------------ */
@@ -1072,6 +1080,7 @@ int __libc_accept(int s, struct sockaddr *addr, socklen_t *addrlen);
 __attribute__((weak))
 int accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
+   wait_for_fd_to_be_readable_or_erring(s);
    return __libc_accept(s, addr, addrlen);
 }
 
@@ -1469,6 +1478,7 @@ int select ( int n,
 typedef unsigned long int nfds_t;
 #endif
 
+
 /* __attribute__((weak)) */
 int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 {
@@ -1552,6 +1562,21 @@ int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 }
 
 
+/* Helper function used to make accept() non-blocking.  Idea is to use
+   the above nonblocking poll() to make this thread ONLY wait for the
+   specified fd to become ready, and then return. */
+static void wait_for_fd_to_be_readable_or_erring ( int fd )
+{
+   struct pollfd pfd;
+   fprintf(stderr, "wait_for_fd_to_be_readable_or_erring %d\n", fd);
+   pfd.fd = fd;
+   pfd.events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLNVAL;
+   /* ... but not POLLOUT, you may notice. */
+   pfd.revents = 0;
+   (void)poll(&pfd, 1, -1 /* forever */);
+}
+
+
 /* ---------------------------------------------------------------------
    Hacky implementation of semaphores.
    ------------------------------------------------------------------ */

diff --git a/coregrind/vg_scheduler.c b/coregrind/vg_scheduler.c
index 1c6dfede1dedb1b171a7d5f305b6f7fea411ad05..5f023dae2617a79ed05f5a6bc55bb642fbb915d1 100644 (file)
--- a/coregrind/vg_scheduler.c
+++ b/coregrind/vg_scheduler.c
@@ -33,10 +33,7 @@
 #include "valgrind.h" /* for VG_USERREQ__MAKE_NOACCESS and
                          VG_USERREQ__DO_LEAK_CHECK */
 
-/* BORKAGE/ISSUES as of 14 Apr 02
-
-Note!  This pthreads implementation is so poor as to not be
-suitable for use by anyone at all!
+/* BORKAGE/ISSUES as of 23 May 02
 
 - Currently, when a signal is run, just the ThreadStatus.status fields 
   are saved in the signal frame, along with the CPU state.  Question: 
@@ -55,18 +52,14 @@ suitable for use by anyone at all!
 - Read/write syscall starts: don't crap out when the initial
   nonblocking read/write returns an error.
 
-- Get rid of restrictions re use of sigaltstack; they are no longer
-  needed.  
-
-- Fix signals properly, so that each thread has its own blocking mask.
-  Currently this isn't done, and (worse?) signals are delivered to
-  Thread 1 (the root thread) regardless.  
-
-  So, what's the deal with signals and mutexes?  If a thread is
+- So, what's the deal with signals and mutexes?  If a thread is
   blocked on a mutex, or for a condition variable for that matter, can
   signals still be delivered to it?  This has serious consequences --
   deadlocks, etc.
 
+- Signals still not really right.  Each thread should have its
+  own pending-set, but there is just one process-wide pending set.
+
 */
 
 

diff --git a/vg_libpthread.c b/vg_libpthread.c
index 46d1c65a7949188e2c0faef47c58ff44d4b22212..6cd7e40d0cf91166c417c386cdbe5068b7953b04 100644 (file)
--- a/vg_libpthread.c
+++ b/vg_libpthread.c
@@ -61,6 +61,14 @@
 #include <sys/time.h>
 #endif
 
+
+/* ---------------------------------------------------------------------
+   Forwardses.
+   ------------------------------------------------------------------ */
+
+static void wait_for_fd_to_be_readable_or_erring ( int fd );
+
+
 /* ---------------------------------------------------------------------
    Helpers.  We have to be pretty self-sufficient.
    ------------------------------------------------------------------ */
@@ -1072,6 +1080,7 @@ int __libc_accept(int s, struct sockaddr *addr, socklen_t *addrlen);
 __attribute__((weak))
 int accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
+   wait_for_fd_to_be_readable_or_erring(s);
    return __libc_accept(s, addr, addrlen);
 }
 
@@ -1469,6 +1478,7 @@ int select ( int n,
 typedef unsigned long int nfds_t;
 #endif
 
+
 /* __attribute__((weak)) */
 int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 {
@@ -1552,6 +1562,21 @@ int poll (struct pollfd *__fds, nfds_t __nfds, int __timeout)
 }
 
 
+/* Helper function used to make accept() non-blocking.  Idea is to use
+   the above nonblocking poll() to make this thread ONLY wait for the
+   specified fd to become ready, and then return. */
+static void wait_for_fd_to_be_readable_or_erring ( int fd )
+{
+   struct pollfd pfd;
+   fprintf(stderr, "wait_for_fd_to_be_readable_or_erring %d\n", fd);
+   pfd.fd = fd;
+   pfd.events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLNVAL;
+   /* ... but not POLLOUT, you may notice. */
+   pfd.revents = 0;
+   (void)poll(&pfd, 1, -1 /* forever */);
+}
+
+
 /* ---------------------------------------------------------------------
    Hacky implementation of semaphores.
    ------------------------------------------------------------------ */

diff --git a/vg_scheduler.c b/vg_scheduler.c
index 1c6dfede1dedb1b171a7d5f305b6f7fea411ad05..5f023dae2617a79ed05f5a6bc55bb642fbb915d1 100644 (file)
--- a/vg_scheduler.c
+++ b/vg_scheduler.c
@@ -33,10 +33,7 @@
 #include "valgrind.h" /* for VG_USERREQ__MAKE_NOACCESS and
                          VG_USERREQ__DO_LEAK_CHECK */
 
-/* BORKAGE/ISSUES as of 14 Apr 02
-
-Note!  This pthreads implementation is so poor as to not be
-suitable for use by anyone at all!
+/* BORKAGE/ISSUES as of 23 May 02
 
 - Currently, when a signal is run, just the ThreadStatus.status fields 
   are saved in the signal frame, along with the CPU state.  Question: 
@@ -55,18 +52,14 @@ suitable for use by anyone at all!
 - Read/write syscall starts: don't crap out when the initial
   nonblocking read/write returns an error.
 
-- Get rid of restrictions re use of sigaltstack; they are no longer
-  needed.  
-
-- Fix signals properly, so that each thread has its own blocking mask.
-  Currently this isn't done, and (worse?) signals are delivered to
-  Thread 1 (the root thread) regardless.  
-
-  So, what's the deal with signals and mutexes?  If a thread is
+- So, what's the deal with signals and mutexes?  If a thread is
   blocked on a mutex, or for a condition variable for that matter, can
   signals still be delivered to it?  This has serious consequences --
   deadlocks, etc.
 
+- Signals still not really right.  Each thread should have its
+  own pending-set, but there is just one process-wide pending set.
+
 */
 
 

diff --git a/vg_syscall_mem.c b/vg_syscall_mem.c
index 3cffd775b72f6f3e49f1b9230fb1da6a4bc9bc99..8331737933d557027b5aed317faae2983f9094a7 100644 (file)
--- a/vg_syscall_mem.c
+++ b/vg_syscall_mem.c
@@ -2334,7 +2334,7 @@ void VG_(perform_assumed_nonblocking_syscall) ( ThreadId tid )
 
       case __NR_sched_setparam: /* syscall 154 */
          /* int sched_setparam(pid_t pid, const struct sched_param *p); */
-         if (VG_(clo_instrument))
+         if (VG_(clo_trace_syscalls))
             VG_(printf)("sched_setparam ( %d, %p )\n", arg1, arg2 );
          must_be_readable( tst, "sched_setparam(ptr)",
                            arg2, sizeof(struct sched_param) );
@@ -2345,7 +2345,7 @@ void VG_(perform_assumed_nonblocking_syscall) ( ThreadId tid )
 
       case __NR_sched_getparam: /* syscall 155 */
          /* int sched_getparam(pid_t pid, struct sched_param *p); */
-         if (VG_(clo_instrument))
+         if (VG_(clo_trace_syscalls))
             VG_(printf)("sched_getparam ( %d, %p )\n", arg1, arg2 );
          must_be_writable( tst, "sched_getparam(ptr)",
                            arg2, sizeof(struct sched_param) );
@@ -2356,7 +2356,7 @@ void VG_(perform_assumed_nonblocking_syscall) ( ThreadId tid )
 
       case __NR_sched_yield: /* syscall 158 */
          /* int sched_yield(void); */
-         if (VG_(clo_instrument))
+         if (VG_(clo_trace_syscalls))
             VG_(printf)("sched_yield ()\n" );
          KERNEL_DO_SYSCALL(tid,res);
          break;